“There has been a large downward trend in mobility that goes back at least a few decades and (it) has been there as prices go up and down,” he said.

Schulhofer-Wohl and his research partner see a bigger factor keeping workers from moving as much: local labor markets are growing more uniform and less specialized. There aren’t very many places like Silicon Valley boasting a strong concentration of one kind of job.

“The kinds of jobs you can get and the money you can earn varies less around the country than they used to,” he said. “There’s less reason to move because of the kind of job you can get.” ...

... Even as Americans are making fewer moves between states, Sinclair’s own research suggests workers are mobile in a different way: they’re willing to move to new professions. Sinclair saw a pattern when studying use of the online job website Indeed.com.

“One of the dramatic things we’re seeing is that people are very keen to look at other occupations,” she said.

Emphasis added. Silicon Valley has niche thick labor market. You can move around within the industry easily. Startup failed? No problem, plenty of other tech jobs open for you in the Bay Area. In other regional job markets, there are more opportunities for a career shift. You don't have to stay a techie in Pittsburgh.